1. Field of the Invention
The present invention relates to a pressure furnace for treating products at high temperature and high pressure. It contains a furnace chamber which is enclosed in a pressure chamber and insulated from the walls of the pressure chamber by an insulating casing. The pressure chamber is built up of a high pressure cylinder and end closures projecting into this cylinder and is surrounded during the pressing by a press stand which takes up axial, outwardly-directed forces acting on the end closures. The pressure furnace is of the type which is charged from below with the aid of a manipulator which is intended to transport a furnace bottom with a charge resting thereon from a preheat furnace and to move the bottom and the charge into the furnace. A pressure furnace charged from below, which is substantially different from the pressure furnace according to the invention only with regard to the charging mechanism and certain constructional parts, is described in detail in U.S. Pat. No. 3,695,597.
Despite the good insulation between the furnace chamber and the pressure chamber walls, the heat losses in furnaces with large dimensions are so great that it is necessary to cool the pressure chamber walls so that their temperature is maintained below an acceptable level with regard to the resistance of the materials of which they are formed. Often it is particularly important that the area around seals between a pressure chamber cylinder and end closures and the area in the end closures should be cooled so that the material in the seals is not destroyed by too high a temperature. Particularly in furnaces which are charged from below, having a furnace bottom which carries the charge during the heating in a preheat furnace and which is transferred to the pressure chamber of the pressure furnace together with the heated charge, it has been found to be difficult to supply coolant to the furnace bottom. The connection between the furnace bottom and the source of the coolant must be easily disconnectible in such a way that there is no risk of losing an appreciable amount of coolant which may cause damage to the furnace.